Avaliação do teor de manganês em alimentos procedentes do município de Simões Filho - BA

Abstract

Background: Manganese (Mn) is an important essential micronutrient involved in bone mineralization, especially for growing children. However, it can also be a neurotoxin if high exposure levels surpass the body homeostatic mechanisms. Objective: To detect the manganese concentration in food crops grown in the vicinity of a ferro-alloy plant in order to evaluate the quality of products cultivated in such impacted area and food also supplied by the Government to the day care-school of Cotegipe, district of Simões Filho - Bahia. Methods: Mn levels in banana (Musa paradisiaca L.), acerola (Malpighia punicifolia) and in fermented manioc (Manihot utilissima) flour were determined by electrothermal atomic absorption spectrometry. Food crops were sampled (n=20 of each) in two areas between 2007-2008: Cotegipe de baixo (Cb) close to the plant (avg. distance 1.5 km) and Cotegipe de cima (Cc) a hill area a little bit further and not in the wind direction (avg. distance 2.5 Km). Results: Mean Mn levels in acerola were 18.69±8.79 mg.Kg-1 and 28.13±13.57 mg.Kg-1 , for CC and CB, respectively. In banana, mean Mn levels were 93.60±41.03 mg.Kg-1 and 66.73±62.23 mg.Kg-1 for CC and CB, respectively. In manioc flower, locally known as "puba", mean Mn levels were 2.26±1.29 mg.Kg-1 and 2.64±1.51 mg.Kg-1 in CC and CB, respectively. Mn contents in fruits grown in Cotegipe Village are very high when compared to literature values 0.7 mg.Kg-1 for acerola and 4.2-6.7 mg.Kg-1 for banana). It is also approximately 4 to 5 times higher in manioc flower when compared to reported values (0.5 mg.Kg-1 ). Statistical difference in mean Mn levels between products from the two localities was only observed for acerola (p=0.015). Conclusion: The results show that the Mn levels in food product locally grown in the vicinity of a ferro-alloy plant are vey high, reaching Mn contents that surpass the estimated safe daily ingestion of Mn (2-5 mg/day).